<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <!--关键代码-->
    <script th:src="@{/webjars/jquery/3.2.1/dist/jquery.min.js}"></script>
    <script th:src="@{/webjars/bootstrap/4.3.1/js/bootstrap.min.js}"></script>
    <link rel="stylesheet" th:href="@{/webjars/bootstrap/4.3.1/css/bootstrap.min.css}"/>
    <link type="text/css" rel="stylesheet" th:href="@{/static/css/style.css}">
</head>
<body>
<img th:src="@{${fileName}}" alt="看到我说明挂了。。。" class="img-rounded"/>
</body>
</html>